Finally figured out why the auto-avatar sizing wasn't working and have set it up to work. This means all avatars are kept below a certain width. This keeps the margins on the left consistent so that the right side, with the text of posts, doesn't get squished down -- and means people don't need to worry about getting the exact size themselves if their file is a little bit large.
Right now it will automatically resize avatars to 120 pixels wide (the board default was only 90, so I made it a bit larger). It doesn't affect the size of your original, wherever you are linking from! It just resizes the image on the fly.